Tissue adhesives have many potential medical applications, including wound closure, supplementing or replacing sutures or staples in internal surgical procedures, preventing leakage of fluids such as blood, bile, gastrointestinal fluid and cerebrospinal fluid, adhesion of synthetic onlays or inlays to the cornea, drug delivery devices, and as anti-adhesion barriers to prevent post-surgical adhesions. Conventional tissue adhesives are generally not suitable for a wide range of adhesive applications. For example, cyanoacrylate-based adhesives have been used for topical wound closure, but the release of toxic degradation products limits their use for internal applications. Fibrin-based adhesives are slow curing, have poor mechanical strength, and pose a risk of viral infection. Additionally, fibrin-based adhesives do not bond covalently to the underlying tissue.
Several types of hydrogel tissue adhesives have been developed, which have improved adhesive and cohesive properties and are nontoxic (see for example Sehl et al., U.S. Patent Application Publication No. 2003/0119985, and Goldmann, U.S. Patent Application Publication No. 2005/0002893). These hydrogels are generally formed by reacting a component having nucleophilic groups with a component having electrophilic groups, which are capable of reacting with the nucleophilic groups of the first component, to form a crosslinked network via covalent bonding. However, these hydrogels typically swell, dissolve away too quickly, or lack sufficient adhesion or mechanical strength, thereby decreasing their effectiveness as surgical adhesives.
Kodokian et al. (copending and commonly owned U.S. Patent Application Publication No. 2006/0078536) describe a polysaccharide-based hydrogel tissue adhesives formed by reacting an oxidized polysaccharide with a water-dispersible, multi-arm polyether amine. These adhesives provide improved adhesion and cohesion properties, crosslink readily at body temperature, maintain dimensional stability initially, do not degrade rapidly, and are nontoxic to cells and non-inflammatory to tissue. However, for certain applications, such as the prevention of undesired tissue-to tissue-adhesions resulting from trauma or surgery, a more rapidly degrading hydrogel tissue adhesive is needed. For example, an adhesion prevention composition should not persist at the site once the healing process has begun, typically not longer than 1 to 3 weeks.
Therefore, the need exists for a hydrogel tissue adhesive that has the desirable properties of the oxidized polysaccharide-based tissue adhesives described by Kodokian et al., supra, but has a shorter degradation time.